个人简介

BS, Brigham Young, University (1977) Ph.D., University of Wisconsin (1981) Postdoctoral Research, Indiana University (1981-82) Visiting Scientist, Joint Research Center, Ispra, Italy (1989-90, 1998-1999) Visiting Professor, University of Utah (2003) Awards: Spectrochimica Acta Atomic Spectroscopy Award (1998, 2006) Lester W. Strock Award (2006) Utah Award, American Chemical Society (2006) Distinguished Service Award, SAS (2009) Karl G. Maeser Research and Creative Works, BYU (2009) College Distinguished Faculty Citizenship, BYU (2010)

研究领域

Analytical Chemistry

My major area of research interest is analytical spectroscopy, with an emphasis on the development of new analytical techniques and instrumentation for trace molecular and elemental analysis. My group’s efforts are divided between two projects: the development and fundamental characterization of ambient ionization sources for molecular mass spectrometry, and studies of ion production and transport in plasma source mass spectrometers. Changes in instrument response with changes in sample composition present a major challenge to users of ICP-MS. With laser excited atomic and ionic fluorescence, we measure ion densities and velocities at various locations in the differentially-pumped vacuum interface that separates the ICP from the mass spectrometer. We are using those measurements to develop a better understanding of how ions are transmitted through the interface, and how that transmission is affected by sample matrix. A second set of experiments focuses on new atmospheric-pressure ionization techniques for mass spectrometric analysis, including DESI and DART. These new ion sources are capable of rapid analysis of a variety of samples with little or no sample preparation. However, the mechanisms by which they work have not yet well understood. We are drawing on our expertise in plasmas to develop a clearer understanding of the complex gas-phase chemistry that controls the performance of plasma-based ambient ionization sources and to develop new sensitive ambient ionization sources. Work in my research group is challenging, yet rewarding. My students gain valuable exposure to mainstream analytical techniques, and at the same time gain practical experience with lasers, mechanical and electrical design, signal acquisition, and sophisticated data processing. Additional research areas: Environmental chemistry, physical chemistry and spectroscopy

近期论文

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J. H. Macedone, Dennis J. Gammon and Paul B. Farnsworth, “Factors Affecting Analyte Transport. Through the Sampling Orifice of an Inductively Coupled Plasma Mass Spectrometer,” Spectrochimica. Acta 56B, 1687-1695 (2001).. Jeffrey H. Macedone, Andrew A. Mills and Paul B. Farnsworth, “Optical Measurements of Ion. Trajectories through the Vacuum Interface of an Inductively Coupled Plasma Mass. Spectrometer,” Applied Spectroscopy, 58, 463-467 (2004).. R. Todd Bronson, David J. Michaelis, Randy D. Lamb, Ghaleb A. Husseini, Paul B. Farnsworth, Matthew. R. Linford, Reed M. Izatt, Jerald S. Bradshaw, and Paul B. Savage, “Efficient Immobilization of a. Cadmium Chemosensor in a Thin Film: Generation of a Cadmium Sensor Prototype,” Organic Letters, 7,. 1105-1108 (2005).. Uchenna P. Paul, Li Li, Milton L. Lee and Paul B. Farnsworth, “Compact Detector for Proteins Based on. Two-Photon Excitation of Native Fluorescence,” Anal. Chem. 77(11), 3690-3693 (2005).. W. Neil Radicic, Jordan B. Olsen, Rebecca V. Nielson, Jeffrey H. Macedone, and Paul B. Farnsworth,. “Characterization of the Supersonic Expansion in the Vacuum Interface of an Inductively Coupled. Plasma Mass Spectrometer by High-Resolution Diode Laser Spectroscopy,” Spectrochimica Acta, 61B,. 686-695 (2006).. Jikun Liu, Xuefei Sun, Paul B. Farnsworth, and Milton L. Lee, “Fabrication of Conductive Membrane in. a Polymeric Electric Field Gradient Focusing Microdevice,” Analytical Chemistry, 78, 4654-4662 (2006).. Jordan B. Olsen, Jeffrey H. Macedone and Paul B. Farnsworth, “Source Gas Kinetic Temperatures in an. ICP-MS Determined By Measurements of the Gas Velocities in the First Vacuum Stage,” Journal of. Analytical Atomic Spectrometry, 21, 856-860 (2006).. Jeffrey Macedone and Paul B. Farnsworth, “Changes in Plasma Composition During the Expansion into. the First Vacuum Stage of an inductively Coupled Plasma Mass Spectrometer,” Spectrochimica. Acta, 61B, 1031-1038 (2006).. Andrew A. Mills, Jeffrey H. Macedone, and Paul B. Farnsworth, “High Resolution Imaging of Barium. Ions and Atoms near the Sampling Cone of an Inductively Coupled Plasma Mass. Spectrometer,” Spectrochimica Acta, 61B, 1039-1049 (2006).. Paul H. Humble, John N. Harb, H. Dennis Tolley, Adam T. Woolley, Paul B. Farnsworth, and Milton L.. Lee, “Influence of Transport Properties in Electric Field Gradient Focusing,” Journal of Chromatography. A, 1160, 311-319 (2007).. Xufei Sun, Paul B. Farnsworth, Adam T. Woolley, H. Dennis Tolley, Karl F. Warnick, and Milton L.. Lee, “Poly(ethylene glycol)-Functionalized Devices for Electric Field Gradient Focusing,” Analytical. Chemistry, 80, 451-460 (2008).. Xufei Sun, Paul B. Farnsworth, H. Dennis Tolley, Karl F. Warnick, Adam T. Woolley, and Milton L.. Lee, “Performance Optimization in Electric Field Gradient Focusing,” Journal of Chromatography. A, 1216, 159-164 (2009).. Haibin Ma, Nicolas Taylor, and Paul B. Farnsworth, “The Effect of the Sampling Interface on Spatial. Distributions of Barium Ions and Atoms in an Inductively Coupled Plasma Ion Source,” Spectrochimica. Acta, 64B, 384-391 (2009).. Michael C. Wood, Devin K. Busby, and Paul B. Farnsworth, “Microscopic Imaging of Glass Surfaces. under the Effects of Desorption Electrospray Ionization,” Analytical Chemistry, 81, 6407-6415 (2009).. Paul B. Farnsworth, Ross L. Spencer, W. Neil Radicic, Nicholas Taylor, Jeffrey Macedone, Haibin Ma,. “A comparison of ion and atom behavior in the first stage of an inductively coupled plasma mass. spectrometer vacuum interface: Evidence of the effect of an ambipolar electric field,” Spectrochimica. Acta, 64B, 905-910 (2009).. Ross L. Spencer, Nicholas Taylor, and Paul B. Farnsworth, “Comparison of calculated and experimental. flow velocities upstream from the sampling cone of an inductively coupled plasma mass. spectrometer,” Spectrochimica Acta, 64B, 921-924 (2009).. James A. Holcombe and Paul B. Farnsworth, “Atomic Emission and Fluorescence Theory,” in: John. Linden, George Tranter and David Koppenaal, editors. Encyclopedia of Spectroscopy and Spectrometry,. 2nd edition, Vol 1. Oxford: Elsevier; 2010. pp 63-69.. Matthew S. Heywood and Paul B. Farnsworth, “Optimization of Native Fluorescence Detection of. Proteins Using a Pulsed Nanolaser Excitation Source,” Applied Spectroscopy, 64, 1283-1288 (2010).. Matthew S. Heywood, Nicholas Taylor, and Paul B. Farnsworth “Measurement of Helium Metastable. Atom Densities in a Plasma-Based Ambient Ionization Source,” Analytical Chemistry, 83, 6493-6499. (2011).. Nicholas Taylor, Ross L. Spencer, and Paul B. Farnsworth, “The effect of matrix composition on radially. resolved argon metastable atom populations in an emission ICP,” Journal of Analytical Atomic. Spectrometry, 27,857-867 (2012)..